India has estimated the price of Himalayan water dependence. Bangladesh should follow suit

India has calculated how much of its economy depends on the Himalayas. 

According to "Prosperous and Resilient Himalayas", a report produced by Systemiq with the Integrated Mountain Initiative, ICIMOD, and India's GB Pant National Institute of Himalayan Environment, Himalayan systems directly underpinned 21.5% of India's FY2024 GDP — Rs64.8 lakh crore. 

Most of that value was captured downstream in the irrigated wheat fields of the Gangetic plains, industrial hubs, municipal grids, and state power systems.

Bangladesh, lower down the same rivers and far more dependent on them, has no figure at all. Lacking data, the country is blind to the fluid foundation of its economy, and it is causing significant gaps on three fronts. 

Bangladesh has never priced its economic dependence on Himalayan water; it barely monitors the glaciers and snow that feed its rivers; and it is denied real-time data on upstream dams that would let it see trouble coming. 

Blind on all three counts, the country can neither cost, watch, nor anticipate the fluid foundation of its economy.

And there is a clock ticking: Hydrologists expect "peak water" around mid-century, after which dry-season flow declines for good. And we have yet to prepare ourselves for the looming crisis. 

Golam Rasul, professor of Economics at IUBAT and former Chief Economist at the International Centre for Integrated Mountain Development (ICIMOD), points to a sense of fatalism born out of downstream powerlessness. 

"We do not have much work in Bangladesh specifically on Himalayan glaciers," he observes. "The reason is that we are downstream. Bangladesh was formed by depositing Himalayan silt carried downstream. So in that sense, we are very much part of the Himalayan system. But when we talk about glaciers, there is a question of how relevant they are when the water isn't under our control."

When upstream dams divert dry-season flows, downstream policymakers begin viewing water volume as an arbitrary political variable rather than a natural asset to be systematically budgeted.

"This is why, although glacier melt and Himalayan snow provide a huge potential benefit, we do not have control over it," says Rasul. "And when a large and powerful country is upstream, it is often reluctant to give up control. Water is not simply water. Water is life, but at times water can also be a weapon."

Around 80% of the annual flow in the major rivers arrives in the four monsoon months; through the long dry season, Rasul notes, Himalayan snow and glacier melt contribute an estimated 9-10% of the Ganges flow at the Hardinge Bridge and 3-5% of the Brahmaputra at Bahadurabad. 

As a fraction of the year's water, these are minor figures. As a fraction of the water available when there is almost none, they are the difference between a harvest and a failure.  

"Failure to understand and manage shared risks can impose costs across an entire basin, not only at its downstream end. Extreme events, infrastructure losses, changing water availability, sediment problems and disrupted livelihoods can affect upstream and downstream communities in different ways." Anik Bhaduri, director, Asia Science Mission and executive director, Sustainable Water Future Programme

What it takes to count

Anik Bhaduri, director of the Asia Science Mission and executive director of the Sustainable Water Future Programme, insists that the cost of non-cooperation and the value of shared water can indeed be counted — provided the methodology moves past old, static models.

"A single monetary figure is not enough to capture Bangladesh's vulnerability," Bhaduri cautions. "Estimates change with climatic, hydrological, and economic conditions. Valuation and attribution are also different. Estimating the value of damage does not establish that one upstream action caused the entire loss. Any estimate needs a defined scenario, clear assumptions, and explicit uncertainty.

"Failure to understand and manage shared risks can impose costs across an entire basin, not only at its downstream end. Extreme events, infrastructure losses, changing water availability, sediment problems and disrupted livelihoods can affect upstream and downstream communities in different ways," he added. 

For decades, Bangladesh's transboundary water posture has been purely reactive. At bilateral meetings, Bangladeshi delegations request water-sharing formulas or flood warnings. When discussions stall, progress stops.

Mohammed Abdul Baten, assistant professor at the Department of Political Science and Sociology, North South University, argued that Bangladesh must abandon this passive posture and build its own active research capacity.

"As a downstream country, our ecosystems, people's livelihoods, and the wider economy will all be affected in one way or another by what happens to the glaciers," he said, adding, "Glacier research is directly connected to climate change research. And because many of our rivers originate directly in the Himalayan region, the condition of those glaciers is directly linked to those river systems."

Baten pointed out that non-mountainous nations regularly conduct glaciological research through international partnerships. European and American universities maintain permanent monitoring programmes in the Himalayas alongside host nations like Nepal.

He further said that Bangladesh could develop research centres or collaborative programmes where research teams from Bangladesh work with counterparts in the Himalayan region. 

"We could pursue SAARC-level collaboration with Nepal on glacier research or collaborate with China and India," Baten suggested.

Crucially, he emphasised that water governance cannot be separated from the man-made structures built upon the rivers. "At present, when we discuss water cooperation with India, our discussions are largely confined to surface-water levels. But we need information about the natural forces — water, glaciers, and mountains — and simultaneously about the hydropower stations, dams, and barrages built across these river systems. Simply receiving water-flow data multilaterally will not provide much benefit. We need multilateral information about the man-made structures that influence and regulate those water flows as well."

Peak water and the looming disaster by mid-century 

Glacio-hydrological research, such as studies by McDowell et al., shows the mechanics of peak water. Warming initially increases annual glacier runoff, driving up river discharge. Communities downstream experience this as intensified summer flooding, higher sediment loads, and bank erosion, even as dry-season flows briefly hold.

However, once a glacier crosses its mass-loss threshold, runoff reaches a peak and begins a long decline.

In the Ganges and Brahmaputra basins, hydrologists project peak water around mid-century. It will cause a progressive depletion of the dry-season freshwater cushion. That cushion is what holds the sea at bay. 

World Bank research on climate-induced salinity finds that reduced dry-season flow lets saline tides push further inland and that soil salinity across the south-west coastal districts already depresses rice yields; as upstream flows diminish, the same studies warn, saltwater is likely to spread across farmland and add to the pressure on the Sundarbans. It is a slow loss rather than a sudden one — which is precisely why it is easy to defer. 

Elsewhere, the gaps have been filled

Bangladesh's predicament can feel like the natural condition of a downstream country. It is not. In other shared basins, riparian states treat river data as something close to a public utility, and they have built the institutions to prove it.

On the Mekong, the four lower riparian states — Cambodia, Laos, Thailand and Viet Nam — run a basin-wide network of automated stations that relay water-level and rainfall readings at near real-time intervals into a shared database, feeding a common flood-and-drought forecasting system. 

Even the upstream giant takes part; China, which is not a member of the Mekong River Commission but a "dialogue partner", has shared hydrological data from two stations in Yunnan since 2002 — but for 18 years only during the flood season, extending to year-round data solely in 2020, and only after a severe drought and sustained international pressure. 

Yet even that is far more than the Brahmaputra's downstream nations are given.

The Rhine goes further. Switzerland, France, Germany, Luxembourg, and the Netherlands, together with the European Union, operate under a legally binding convention that harmonises monitoring across the entire watershed, coordinated by the International Commission for the Protection of the Rhine. 

Under its International Warning and Alarm Plan, a pollution spike or flood wave detected upstream triggers immediate notification to the states below through designated warning centres — routine, standardised and stripped of diplomacy.

The Senegal River goes farthest. Mali, Mauritania, Senegal and Guinea jointly own the river's major dams, Manantali and Diama, as 'common and indivisible' property, sharing both the costs and the revenues through the Organisation pour la mise en valeur du fleuve Sénégal.

What Bangladesh can do 

Bhaduri is clear that the fix begins with evidence, not diplomacy. The priority, he said, is to understand the basin as a single connected system, and the tools to do so have improved out of recognition, from Earth observation and remote sensing to hydrological modelling and machine learning. 

"Bringing these sources together with ground observations can substantially improve flood and drought forecasting, risk assessment and our knowledge of changes across the basin. Scientists are capable of contributing by developing transparent methods, comparable indicators, interoperable datasets, joint modelling approaches, shared forecasting tools and joint research." 

The point, though, is not to accumulate data for its own sake. "The goal should not simply be more data," Bhaduri said, "It should be a better common understanding." 

How states formalise data-sharing is ultimately a matter for governments; but the scientific case for timely, reliable and comparable information is straightforward, because floods, droughts and shifting sediment loads do not stop at a border.

Sheikh Rokon, founder and secretary general of Riverine People, pressed on the same argument to its harder edge.

"Even full readings from Nepal, Bhutan and China would not be enough on their own. What Bangladesh lacks is information about the structures that now govern the rivers. We also need information about the natural forces involved — water, glaciers, and mountains," he said. 

"At the same time, we need information about the hydropower stations, dams and barrages that have been built across these river systems."